Ignite is an event where speakers have 5 minutes to present 20 slides that are auto-advanced every 15 seconds. It is a bit like speed chess where timing is a big part of the game.
Interesting survey data from Scott Berkun on how speakers prepare for ignite presentations.
Conclusion is that excellent speeches take a lot of preparation, even for pros, and that generally speakers don’t rehearse enough.
Why are professional speakers so good? One explanation is that they do a speech many times to improve it. They also prepare and rehearse more than regular speakers.